Rotating drum structures have been used to coat small particulate material, including seeds, pharmaceutical products, and food items such as breakfast cereals. Applicant's U.S. Pat. No. 5,443,637 discloses a continuous coating machine, while applicant's U.S. Pat. No. 5,376,175 discloses a batch coating machine. In both batch and continuous coating processes, the rotatable drum is perforated to allow air to pass therethrough so as to enhance drying of the liquid coating which is sprayed on to the particulate material. In such prior art machines, the perforated side wall of the drum is formed in one piece with perforations being a specific size. Particulates smaller than the perforations cannot be coated in the drum, since the particulate could pass through the perforations. Interchangeable drums may be used with each drum having different size perforations. The drums in a continuous coating machine are typically eight feet long and thus awkward and heavy to handle. Therefore, the physical exchanging of drum is time consuming and difficult.
Accordingly, a primary objective of the present invention is the provision of an improved rotatable drum for a particulate material coating machine wherein the drum includes interchangeable perforated panels.
Another objective of the present invention is the provision of a drum or reel for a particulate material coating machine including a drum frame and slidably mounted screen panels.
A further objective of the present invention is the provision of a particulate material coating machine wherein the size of the perforations in the drum can be quickly and easily changed to accommodate different sized particulate.
Another objective of the present invention is the provision of a machine for coating particulate material which is economical to manufacturer, and efficient and durable in use.
These and other objectives become apparent from the following description of the invention.